NEW YORK (AFP) -- Federal Reserve Chair Janet Yellen expressed confidence in U.S. economic growth Tuesday but stuck to a dovish stance on monetary policy, saying the Fed still had to keep its eye on international economic and financial frailty.With markets on edge over when the Fed will next raise interest rates, which would increase the cost of money for borrowers worldwide, Yellen signaled clearly that was not likely to come before June and that, when the U.S. central bank does tighten policy, it will be slow and gradual.“The U.S. economy has proven remarkably resilient,” she told the Economic Club of New York, in her first public remarks since the Fed took a surprisingly dovish stance on monetary policy in its March meeting.Job creation remains strong, and other signs of growth firm, even as U.S. manufacturing industry has been hit by the strong dollar and the sharp contraction in the oil and gas industry, she said.But even if the U.S. economy continues to grow at a moderate pace, the Fed has to pay heed to “broader concerns about global financial developments,” including oil prices and the overall pace of growth, as it weighs tightening monetary policy.Yellen also rejected arguments, including from some Fed officials, that inflation has increased to the point that the policy-setting Federal Open Market Committee needs to raise rates sooner rather than later.She was still not convinced that the signs of a permanent uptick in consumer prices were already evident.“It is too early to tell if this recent faster pace will prove durable,” she said.Her remarks sent stocks higher and the dollar tumbling after markets had expected a slightly more hawkish stance. Since the March FOMC meeting, several other officials have expressed stronger views on inflation picking up and the likelihood of a rate increase by mid-year.Reversing earlier losses, the S&P500 added 0.8 percent in afternoon trade, while the dollar lost about 0.8 percent at $1.1289 per euro. The dollar also fell against the yen and the British pound.“On balance, (Yellen’s) comments do not sound consistent with a looming rate hike in April and leave considerable doubt about whether rates will rise in June,” said Omer Esiner, chief market analyst at Commonwealth Foreign Exchange.Broadly speaking, Yellen said the Fed is holding to its forecasts for moderate U.S. growth and inflation heading to the Fed’s 2.0 percent goal over the medium term, the same view it held in December when the FOMC decided to raise the rock-bottom federal funds rate for the first time in more than nine years.At the time, the FOMC projected another four quarter-point rate increases over this year, taking the fed funds benchmark to 1.25-1.50 percent.But that was scaled back in March to two increases, spurring debate among analysts over whether the Fed was missing the ball or, on the other hand, seeing more dangers to growth than it was letting on.“The baseline economic outlook that the committee saw both in December and March looks quite similar,” Yellen explained.“I would say the major thing that’s changed between December and March that affects the baseline outlook is a slightly weaker projected pace of global growth.”She made clear that she felt the FOMC has room to further watch domestic and global trends. “Given the risks to the outlook, I consider it appropriate for the committee to proceed cautiously in adjusting policy,” she stressed.Enumerating her worries, Yellen pointed specifically to uncertainty about China and how its troubles and its broader economic transition affects global growth.“There is much uncertainty, however, about how smoothly this transition will proceed, and about the policy framework in place to manage any financial disruptions that might accompany it,” she said of China.She also said that the sustained collapse of the market for oil and other key commodities is also keeping a cloud over the global economy, even as cheaper prices benefit consumers and manufacturers.Another sharp fall in oil prices would have an adverse impact on the world economy, she noted.“She is cautious, and sees her caution justified,” said economist Chris Low of FTN Financial, who cut his expectations for Fed rate hikes to just one this year.